PTPN22 gene polymorphism (C1858T) is associated with susceptibility to type 1 diabetes: a meta-analysis of 19,495 cases and 25,341 controls

Comparison of immunological and immunogenetic markers in recent-onset type 1 diabetes among children and adults

This study aimed to compare the immunological and immunogenetic profiles over a spectrum of childhood- and adulthood-onset T1D at diagnosis. The cross-sectional study involved participants with recently diagnosed T1D (n = 168), aged 2.9-68.2 years. HLA-II alleles, single nucleotide polymorphisms (SNP) (rs2476601, rs3087243, rs1990760, rs13266634), thyroid and coeliac disease-related autoantibodies and anti-enterovirus antibodies (anti-EV) were analysed regarding the diabetes-associated autoantibodies' (DAA) status and the age of participants. In the longitudinal study, 19 immune checkpoint gene expression levels in children (n = 25) aged 3.6-14.5 years were measured at diagnosis and 1 year after diagnosis. The duration of symptoms before diagnosis was age-dependent. Older age increased the odds of being single DAA-positive (OR 1.05; 95% CI 1.02-1.09), while anti-EV IgG positivity increased the odds of being multiple DAA-positive (adjusted OR 4.42; 95% CI 1.62-12.04). The DAA-negative T1D participants were older than the DAA-positive individuals. The checkpoint gene expression levels between the two time points were similar, but exhibited more pronounced variability at the time of diagnosis. These results confirm immunological variability in recent-onset T1D cases between children and adults and stress the importance of further research to define the comprehensive immunological profile of the disease age-related subgroups.

Genetics: Is LADA just late onset type 1 diabetes?

BACKGROUND

There is a controversy regarding Latent Autoimmune Diabetes in Adults (LADA) classification and whether it should be considered a slowly progressing form of type 1 (T1) diabetes (DM) or a distinct type of DM altogether.

METHODS

This cross-sectional study assessed major genes associated with T1DM (class II HLA, PTPN22 [rs2476601] and INS [rs689]) in patients with LADA, as compared with participants with T1DM (stratified according to age of diagnosis before or after 30) and T2DM. HLA genotyping of the DRB1, DQA1 and DQB1 loci was performed by reverse PCR sequence-specific oligonucleotides. HLA haplotypes were assigned according to those most frequently described in the European population. INS and PTPN22 SNPs were genotyped by real-time PCR.

RESULTS

A total of 578 participants were included: 248 with T1DM (70 diagnosed after the age of 30), 256 with T2DM and 74 with LADA. High risk HLA alleles were significantly more frequent in LADA than in T2DM, whereas the opposite was true for protective alleles. We found a lower frequency of the high-risk DRB1*04-DQB1*03:02-DQA1*03:01 haplotype in LADA (21.1%) than in the overall T1DM (34.7%) (p<0.05), whereas no differences were found between these groups for DRB1*03-DQB1*02:01-DQA1*05:01 or for protective alleles. Only 12% the overall T1DM group had no risk alleles vs 30% of LADA (p<0.0005). However, HLA allele distribution was similar in LADA and T1DM diagnosed after the age of 30. A total of 506 individuals (195 with T1DM [21 diagnosed after age 30] 253 with T2DM and 58 with LADA) were genotyped for the PTPN22 and INS SNPs. The G/A genotype of the PTPN22 rs2476601 was more frequent and the T/T genotype of the INS SNP rs689 was less frequent in T1DM compared to LADA. We did not find any significant differences in the frequency of the mentioned SNPs between LADA and T2DM, or between LADA and T1DM diagnosed after the age of 30.

CONCLUSION

In this relatively small cross-sectional study, the genetic profile of subjects with LADA showed a similar T1DM-related risk allele distribution as in participants with T1DM diagnosed after the age of 30, but fewer risk alleles than those diagnosed before 30. Differences were present for HLA, as well as PTPN22 and INS genes.

Overexpression of the PTPN22 Autoimmune Risk Variant LYP-620W Fails to Restrain Human CD4+ T Cell Activation

A missense mutation (R620W) of protein tyrosine phosphatase nonreceptor type 22 (PTPN22), which encodes lymphoid-tyrosine phosphatase (LYP), confers genetic risk for multiple autoimmune diseases including type 1 diabetes. LYP has been putatively demonstrated to attenuate proximal T and BCR signaling. However, limited data exist regarding PTPN22 expression within primary T cell subsets and the impact of the type 1 diabetes risk variant on human T cell activity. In this study, we demonstrate endogenous PTPN22 is differentially expressed and dynamically controlled following activation. From control subjects homozygous for the nonrisk allele, we observed 2.1- (p < 0.05) and 3.6-fold (p < 0.001) more PTPN22 transcripts in resting CD4+ memory and regulatory T cells (Tregs), respectively, over naive CD4+ T cells, with expression peaking 24 h postactivation. When LYP was overexpressed in conventional CD4+ T cells, TCR signaling and activation were blunted by LYP-620R (p < 0.001) but only modestly affected by the LYP-620W risk variant versus mock-transfected control, with similar results observed in Tregs. LYP overexpression only impacted proliferation following activation by APCs but not anti-CD3- and anti-CD28-coated microbeads, suggesting LYP modulation of pathways other than TCR. Notably, proliferation was significantly lower with LYP-620R than with LYP-620W overexpression in conventional CD4+ T cells but was similar in Treg. These data indicate that the LYP-620W variant is hypomorphic in the context of human CD4+ T cell activation and may have important implications for therapies seeking to restore immunological tolerance in autoimmune disorders.

Association of variants in PTPN22, CTLA-4, IL2-RA, and INS genes with type 1 diabetes in Emiratis

Type 1 diabetes (T1D) is a chronic autoimmune disease with a complex interrelation of genetic and environmental factors. Genetic studies have reported HLA and non-HLA loci as significant contributors to T1D. However, the genetic basis of T1D among Emiratis is unexplored. This study aims to determine the contribution of four genes PTPN22, CTLA-4, IL2-RA, and INS to T1D risk among Emiratis. The association between variants in PTPN22 (rs2476601, rs1310182), CTLA-4 (rs11571316, rs231775, rs3087243, rs1427676, and rs231727), IL2-RA (rs7090530), and INS (rs7111341) with T1D was tested in 310 Emiratis (139 T1D patients and 171 controls). A significant association was found at rs1310182, and rs2476601 both in PTPN22, rs3087243, and rs231775 both in CTLA-4, and rs12251307 in IL2-RA. Moreover, a haplotype constituted from GG and AG genotypes at rs231727 and rs231775, respectively, in CTLA-4 was significantly associated with an increased T1D risk. The cumulative effects of risk alleles for all significantly associated SNPs showed 11.8 higher relative risk for T1D for those who carry 5-6 compared to 0-1 risk alleles. This study illustrated that PTPN22, CTLA-4, and IL2-RA gene variants could confer risk alleles for T1D among the Emirati population.

Association between interleukin-10 gene polymorphisms and risk of oral carcinoma: A meta-analysis

BACKGROUND

The single nucleotide polymorphisms (SNPs) of Interleukin-10 (IL-10) gene have been linked with the risk of oral carcinoma (OC) in a relatively small sample size. Our study aims to investigate the pooled associations by conducting a meta-analysis of published studies.

METHODS

PubMed, Web of Science and Google Scholar databases were searched to identify eligible studies published in English before October 2019. The odds ratio (OR) with a 95% confidence interval (CI) was used to assess association. The publication bias was detected by Begg's test. Sensitivity and cumulative analyses were performed to evaluate the stability of crude results.

RESULTS

The meta-analysis involved eight studies. Significant associations were certified between IL-10 gene -1082A/G polymorphism and susceptibility of OC for A vs. G (OR=1.817, 95% CI: 1.481-2.230), AA vs. GG (OR=3.436, 95% CI: 2.281-5.175), dominant genetic model (OR=2.913, 95% CI: 1.939-4.376), and recessive genetic model (OR=1.886, 95% CI: 1.372-2.594) in overall population, East Asians and South Asians. In addition, the significant association between -592A/C polymorphism of the gene and susceptibility of OC were detected in South Asians.

CONCLUSIONS

The meta-analysis results support that the IL-10 gene -1082G allele is a risk factor for OC in East Asians and South Asians, and IL-10 gene -592C allele is a protective factor for the disease.

Association between ALMS 1 variants and early-onset coronary artery disease: a case-control study in Chinese population

BACKGROUND

Genome-wide linkage analysis revealed the polymorphism of rs6748040 and glutamic acid repeat are potential pathogenic factors of early-onset myocardial infarction (MI). The present study was designed to investigate the associations of Alström syndrome 1 (ALMS 1) gene in Chinese populations with early-onset coronary artery disease (CAD).

METHODS

The two variants of the ALMS 1 gene were genotyped in 1252 early-onset CAD patients and 1378 controls using PCR, followed by Sml I restriction enzyme digestion or direct sequencing of the PCR product. The associations were estimated using the odds ratio (OR) and the 95% confidence interval (CI).

RESULTS

A significant association between the ALMS 1 G/A variant and the risk of early-onset MI was detected in G vs.A (OR = 1.371, 95% CI: 1.183-1.589), GG vs. AA (OR = 2.037, 95% CI: 1.408-2.948), dominant genetic model (OR = 1.794, 95% CI: 1.254-2.567), and recessive genetic model (OR = 1.421, 95% CI: 1.177-1.716). 14 glutamic acid repeat (A14) is risk factor for early-onset MI (OR = 1.605, 95% CI: 1.313-1.962) and 17 glutamic acid repeat (A17) is protective factor for the disease (OR = 0.684, 95% CI: 0.601-0.827). These associations were not detected in early-onset CAD patients.

CONCLUSIONS

Our findings indicated that G/A variant (rs6748040) and glutamic acid repeat polymorphism of the ALMS 1 gene associated with the risk of early-onset MI in the Chinese population.

Exploiting novel tailored immunotherapies of type 1 diabetes: Short interfering RNA delivered by cationic liposomes enables efficient down-regulation of variant PTPN22 gene in T lymphocytes

In autoimmune diseases as Type 1 diabetes, the actual treatment that provides the missing hormones is not able, however, to interrupt the underlining immunological mechanism. Importantly, novel immunotherapies are exploited to protect and rescue the remaining hormone producing cells. Among probable targets of immunotherapy, the C1858T mutation in the PTPN22 gene, which encodes for the lymphoid tyrosine phosphatase (Lyp) variant R620W, reveals an autoimmunity related pathophysiological role. Our scope was to establish new C1858T PTPN22 siRNA duplexes delivered by liposomal carriers (lipoplexes) to patients' PBMC. Following lipoplexes treatment, CD3+ and CD3- immunotypes were efficiently transfected; cell integrity and viability were preserved. Specific target mRNA down-modulation was observed. After T cell receptor stimulation, in lipoplexes-treated PBMC Lyp function was restored by increased release of IL-2 in cultures. Results set-up the stage for ultimate trials in the treatment of autoimmunity based on the specific inhibitory targeting of C1858T PTPN22 by lipoplexes.

Association of PTPN22 polymorphism and its correlation with Graves' disease susceptibility in Polish adult population-A preliminary study

Background

Susceptibility to Graves' disease (GD) is determined by various genetic factors; the gene encoding protein tyrosine phosphatase (PTPN22) may be one of those associated with higher risk of GD. The aim was to estimate the association of the PTPN22 gene polymorphism rs2476601:c.C>T (c.1858C>T) with the predisposition to GD within the adult north‐eastern Polish population.

Methods

PTPN22 gene polymorphism was analyzed in individuals with clinical GD history (n = 166) and healthy subjects (n = 154). The presence of different variants of the investigated gene polymorphism was estimated using the DNA Sanger sequencing method.

Results

Patients with GD had a more frequent occurrence of the T gene allele of PTPN22 gene compared to the control group, however, it was not significant (p = 0.257). Analysis of genotype distribution showed significantly more frequent occurrence of TT homozygote in GD patients compared to control individuals (p = 0.016, OR = 9.28). Patients with ophthalmopathy had a less frequent occurrence of the T gene allele of PTPN22 gene compared to patients without ophthalmopathy, however, it was not significant (p = 0.12). Occurrence of the T gene allele of PTPN22 gene in GD manifestation in those under 40‐year old was more frequent compared to individuals over 40, but the obtained difference was also not significant (p = 0.75).

Conclusions

Our preliminary study suggest that PTPN22:c.1858C>T gene polymorphism may be associated with a predisposition to GD within the adult north‐eastern Polish population. The studied polymorphism of the PTPN22 gene did not significantly affect the risk of ophthalmopathy developing and disease manifestation before the age of 40.

Role of C1858T Polymorphism of Lymphoid Tyrosine Phosphatase in Egyptian Children and Adolescents with Type 1 Diabetes

BACKGROUND

Type 1 Diabetes Mellitus (T1DM) is a multifactorial autoimmune disease. The Protein Tyrosine Phosphatase Non-receptor 22 (PTPN22) gene is an important negative regulator of signal transduction through the T-cell Receptors (TCR). A PTPN22 polymorphism, C1858T, has been found to be a risk determinant for several autoimmune diseases, including T1DM, in different populations.

OBJECTIVE

The present study was aimed to analyze a possible association between the C1858T polymorphism in Egyptian children with T1DM.

METHODS

This case-control study included 240 children divided evenly between T1DM patients and controls. The PTPN22 C1858T polymorphism was genotyped using polymerase chain reaction with Restriction Fragment Length Polymorphism (RFLP).

RESULTS

Both the 1858CΤ and 1858ΤΤ genotypes and the 1858T allele were found more frequently in patients (32.5% and 18.7%, respectively) than in controls (10% and 5.0%, respectively), P=0.013 and P=0.007, respectively. Among females, the 1858T allele was more common in patients (18%) than in controls (2.6%), P=0.014.

CONCLUSION

These findings suggest that the PTPN22 1858T allele could be a T1DM susceptibility factor in the Egyptian population and that it might play a different role in susceptibility to T1DM according to gender in T1DM patients.

Association of protein tyrosine phosphatase non-receptor type 22 gene functional variant C1858T, HLA-DQ/DR genotypes and autoantibodies with susceptibility to type-1 diabetes mellitus in Kuwaiti Arabs

The incidence of type-1 Diabetes Mellitus (T1DM) has increased steadily in Kuwait during recent years and it is now considered amongst the high-incidence countries. An interaction between susceptibility genes, immune system mediators and environmental factors predispose susceptible individuals to T1DM. We have determined the prevalence of protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene functional variant (C1858T; R620W, rs2476601), HLA-DQ and DR alleles and three autoantibodies in Kuwaiti children with T1DM to evaluate their impact on genetic predisposition of the disease. This study included 253 Kuwaiti children with T1DM and 214 ethnically matched controls. The genotypes of PTPN22 gene functional variant C1858T (R620W; rs2476601) were detected by PCR-RFLP method and confirmed by DNA sequencing. HLA-DQ and DR alleles were determined by sequence-specific PCR. Three autoantibodies were detected in the T1DM patients using radio-immunoassays. A significant association was detected between the variant genotype of the PTPN22 gene (C1858T, rs2476601) and T1DM in Kuwaiti Arabs. HLA-DQ2 and DQ8 alleles showed a strong association with T1DM. In T1DM patients which carried the variant TT-genotype of the PTPN22 gene, 93% had at least one DQ2 allele and 60% carried either a DQ2 or a DQ8 allele. Amongst the DR alleles, the DR3-DRB5, DR3-3, DR3-4 and DR4-4 showed a strong association with T1DM. Majority of T1DM patients who carried homozygous variant (TT) genotype of the PTPN22 gene had either DR3-DRB5 or DRB3-DRB4 genotypes. In T1DM patients who co-inherited the high risk HLA DQ, DR alleles with the variant genotype of PTPN22 gene, the majority were positive for three autoantibodies. Our data demonstrate that the variant T-allele of the PTPN22 gene along with HLA-DQ2 and DQ8 alleles constitute significant determinants of genetic predisposition of T1DM in Kuwaiti children.

Coincidence of PTPN22 c.1858CC and FCRL3 -169CC genotypes as a biomarker of preserved residual β-cell function in children with type 1 diabetes

BACKGROUND

Genotype-phenotype studies in type 1 diabetes (T1DM) patients are needed for further development of therapy strategies.

OBJECTIVE

Our aims were to investigate the distribution of selected PTPN22 and FCRL3 gene polymorphisms and their associations with clinical course of disease in children with newly diagnosed T1DM from the Pomeranian region of Poland.

SUBJECTS/METHODS

The prospective, longitudinal study of 147 children with newly diagnosed T1DM-autoimmune subtype was conducted. The PTPN22 c.1858T>C (rs2476601) and FCRL3 -169C>T (rs7528684) polymorphisms were analyzed using polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) and DNA sequencing. The frequencies of genotypes were compared between the study and population-matched control group (327 random anonymous samples from the Pomeranian region). Selected patients underwent a 24-monthly follow up [periodic re-evaluation of fasting C-peptide concentration (FCP) and hemoglobin A1c (HbA1c ) level].

RESULTS

A significantly lower coincidence of the PTPN22 c.1858CC and FCRL3 -169CC genotypes was found in the study group compared with controls (P = 0.04). The PTPN22 c.1858CC and FCRL3 -169CC genotype combination, restricted to female patients only, was associated with well-preserved residual β-cell function throughout the entire follow up (prolonged FCP level increase up to the sixth month of disease, with further very stable dynamics-FCP median level ≥0.67 ng/mL without significant decrease up to the 24th month). HbA1c levels in this subgroup also remained the lowest during the observation period.

CONCLUSIONS/INTERPRETATION

Ascertained phenomenon could be explained by an interacting mechanism of the two polymorphisms through estrogen-regulated nuclear factor kappa B signaling in regulatory T (T_reg ) lymphocytes. This hypothesis, if confirmed, may lead to further development of T_reg administration-based therapies.

C1858T Polymorphism of Protein Tyrosine Phosphatase Non-receptor Type 22 (PTPN22): an eligible target for prevention of type 1 diabetes?

INTRODUCTION

In type 1 diabetes (T1D), several genetic factors are associated to β-cell autoimmunity onset and clinical progression. HLA-genes play a major role in susceptibility and initiation of β-cell autoimmunity, whereas non-HLA genes may influence the destruction rate. Areas covered: Our review focuses on the possible role of the PTPN22 C1858 T variant as a prognostic factor, given its influence on disease variability. Moreover, we present the potential role of C1858 T as a target for tertiary prevention trials and new therapeutic strategies, such as the LYP inhibitors. We used PubMed for literature research; key words were 'PTPN22', 'C1858 T polymorphism', 'lymphoid-specific tyrosine phosphatase' and 'type 1 diabetes'. We selected publications between 2000 and 2016. Expert commentary: Current data suggest that PTPN22 can be a promising target for therapeutic interventions and identification of at-risk subjects in autoimmune diseases such as T1D.

Dimethylarginine Dimethylaminohydrolase 2 (DDAH 2) Gene Polymorphism, Asymmetric Dimethylarginine (ADMA) Concentrations, and Risk of Coronary Artery Disease: A Case-Control Study

Asymmetric dimethylarginine (ADMA) has been shown to be an independent predictor of cardiovascular diseases. Dimethylarginine dimethylaminohydrolase 2 (DDAH 2) promotes the metabolism of ADMA and plays a key role in the regulation of acute inflammatory response. With the present study, we investigated the relationship between DDAH 2 polymorphisms and risk of coronary artery disease (CAD) and its association to plasma ADMA concentrations. We used the haplotype-tagging SNP approach to identify tag SNPs in DDAH 2. The SNPs were genotyped by PCR and sequenced in 385 CAD patients and 353 healthy controls. Plasma concentrations of ADMA were determined using enzyme-linked immunosorbent assay (ELISA). A promoter polymorphism -449C/G (rs805305) in DDAH 2 was identified. Compared with the ADMA concentrations in CC genotype (0.328 ± 0.077 μmol/l), ADMA concentrations in CG + GG genotype were significantly increased (0.517 ± 0.090 μmol/l, P < 0.001). No significant associations between the -449C/G and risk of CAD were detected in the genetic models. The results of this study suggest that Genetic -499C/G polymorphism in DDAH 2 gene may affect the plasma ADMA concentrations in patients with CAD. However, it does not indicate a novel genetic risk marker for CAD.

Levels of asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, and risk of coronary artery disease: A meta-analysis based on 4713 participants

BACKGROUND

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of endothelial nitric oxide synthase by competing with L-arginine. As a result, the expression of nitric oxide decreases and endothelial dysfunction occurs. Studies have evaluated the association between the serum ADMA level and risk of coronary artery disease. However, conflicting results have been obtained.

METHODS

Pubmed, Web of Science, Embase, Ovid, Cochrane databases were searched to identify eligible studies published in English until December 2014. Association was assessed on the basis of weighted mean differences (WMD) with 95% confidence intervals (CIs). Publication bias was analysed using Begg's and Egger's tests. Sensitivity analysis was performed to evaluate result stability.

RESULTS

A total of 16 case-control studies with 2939 patients and 1774 controls were included in the meta-analysis. Pooled result indicated that patients with coronary artery disease yielded a higher ADMA level than healthy controls (WMD: 0.248, 95% CI: 0.156-0.340; p = 1.16 e-7). Sensitivity analysis suggested that our meta-analysis result was stable. Subgroup analysis found a similar pattern in patients with myocardial infarction (WMD: 0.397, 95% CI: 0.112-0.683; p = 0.0106), stable angina pectoris (WMD: 0.197, 95% CI: 0.031-0.364; p = 0.02) and unstable angina pectoris (WMD: 0.857, 95% CI: 0.293-1.420; p = 0.003).

CONCLUSIONS

Meta-analysis results indicated that an increased ADMA level is associated with an increased risk of coronary artery disease.

Genetic 135G/C polymorphism of RAD51 gene and risk of cancer: a meta-analysis of 28,956 cases and 28,372 controls

The RAD51 gene is essential for the repair of damaged DNA related to tumor development. Although a number of genetic studies have attempted to link the 135G/C polymorphism of RAD51 gene to the risk of cancer, the results were inconclusive. The present study aimed at investigating the pooled association using the more comprehensive meta-analysis. The PubMed, EBSCO, and BIOSIS databases were searched to identify eligible studies which were published in English before March 2014. Data were extracted using standardized methods. The association was assessed by odds ratio (OR) with 95 % confidence interval (CI). Begg's test was used to measure publication bias. Sensitivity analyses were also performed to assess the stability of the results. A total of 45 eligible studies with 28,956 patients and 28,372 controls were included in this meta-analysis. Overall, significant association was detected between 135G/C polymorphism and increased cancer risk (C allele vs. G allele: OR 1.23, 95 % CI 1.18-1.28; CC vs. GG: OR 2.41, 95 % CI 2.12-2.74; CC vs. CG: OR 3.86, 95 % CI 3.41-4.37; recessive model: OR 3.57, 95 % CI 3.19-4.00). In further stratified analysis, significantly elevated cancer risk was observed among Caucasians but not Asians. Subgroup analysis by different cancers also showed their significant associations in breast cancer, hematologic malignances, ovarian cancer, colorectal cancer and endometrial cancer, but not in head and neck cancer. Our results indicated that the RAD51 135G/C polymorphism was a candidate for susceptibility of cancer. The effect of the variants on the expression levels and the possible functional role of the variants in different cancers should be addressed in further studies.

Association of monocyte chemoattractant protein-1 (MCP-1)-2518A>G polymorphism with susceptibility to coronary artery disease: a meta-analysis

We attempted to systematically elucidate the association between monocyte chemoattractant protein-1 (MCP-1) -2518A>G polymorphism and risk of coronary artery disease (CAD). Eligible studies were identified through PubMed, EBSCO, and Web of Science Databases. The magnitude of MCP-1 polymorphism effect and its possible mode of action on CAD were estimated. The odds ratio (OR) with 95% confidence intervals (CI) were pooled in a specific genetic model to assess the association. A total of 21 studies were involved. There was significant gene effect on CAD risk in the overall population (likelihood ratio test: p < 0.0001). Patients with GG and AG genotypes had 1.435 (95% CI: 1.183-1.740) and 1.087 (95% CI: 1.008-1.172) times higher risk of CAD than those with AA genotype. These gene effects suggested a recessive model to be appropriate. The pooled OR was 1.362 (95% CI: 1.137-1.631; puncorrected = 0.001, pFDR = 0.005) in the recessive model. In the ethnicity-stratified analysis, significant association was observed in the Caucasian population (OR = 1.492; 95% CI: 1.106-2.014; puncorrected = 0.009, pFDR = 0.015), whereas no statistical significant association was detected in the Asian population (adjusted p = 0.124). The results suggested that MCP-1 -2518A>G polymorphism may be associated with susceptibility to CAD, especially in Caucasians.

Association between MTHFR polymorphisms and congenital heart disease: a meta-analysis based on 9,329 cases and 15,076 controls

The aim of our study was to evaluate the association between polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and the risk for congenital heart disease (CHD). Electronic literature databases were searched to identify eligible studies published before Jun, 2014. The association was assessed by the odds ratio (OR) with a 95% confidence interval (CI). The publication bias was explored using Begg's test. Sensitivity analysis was performed to evaluate the stability of the crude results. A total of 35 studies were included in this meta-analysis. For the MTHFR C677T polymorphism, we detected significant association in all genetic models for Asian children and the maternal population. Significant association was also detected in T vs. C for a Caucasian paediatric population (OR = 1.163, 95% CI: 1.008-1.342) and in both T vs. C (OR = 1.125, 95% CI: 1.043-1.214) and the dominant model (OR = 1.216, 95% CI:b1.096-1.348) for a Caucasian maternal population. For the MTHFR A1298C polymorphism, the association was detected in CC vs. AC for the Caucasian paediatric population (OR = 1.484, 95% CI: 1.035-2.128). Our results support the MTHFR -677T allele as a susceptibility factor for CHD in the Asian maternal population and the -1298 C allele as a risk factor in the Caucasian paediatric population.

The association of PTPN22 rs2476601 polymorphism and CTLA-4 rs231775 polymorphism with LADA risks: a systematic review and meta-analysis

Although the polymorphisms of PTPN22 and the variants of CTLA-4 have been reported to be the susceptibility genes, which increased risk of latent autoimmune diabetes in adults (LADA), the results remained inconclusive. The aim of this meta-analysis was to evaluate the association between the polymorphisms of two genes and LADA. We performed a systematic review by identifying relevant studies and applied meta-analysis to pool gene effects. Data from ten studies published between 2001 and 2013 were pooled for two polymorphisms: rs2476601 in the PTPN22 gene and rs231775 in the CTLA-4 gene. Data extraction and assessments for risk of bias were independently performed by two reviewers. Fixed-effect model and random-effect model were used to pool the odds ratios; meanwhile, heterogeneity test, publication bias and sensitive analysis were explored. The minor T allele at rs2476601 and the minor G at rs231775 carried estimated relative risks (odds ratio) of 1.52 (95 % CI 1.29-1.79) and 1.39 (95 % CI 1.11-1.74), respectively. These alleles contributed to an absolute lowering of the risk of all LADA by 4.88 and 14.93 % when individuals do not carry these alleles. The estimated lambdas were 0.49 and 0.63, suggesting a codominant model of effects was most likely for two genes. In summary, our systematic review has demonstrated that PTPN22 rs2476601 and CTLA-4 rs231775 are potential risk factors for LADA. An updated meta-analysis is required when more studies are published to increase the power of these polymorphisms and LADA.

Study of factors influencing susceptibility and age at onset of type 1 diabetes: A review of data from Continental Italy and Sardinia

AIM: To investigate the role of protein tyrosin phosphatase 22 (PTPN22), maternal age at conception and sex on susceptibility and age at onset of type 1 diabetes (T1D) in Continental Italy and Sardinian populations.

METHODS: Three hundred seventy six subjects admitted consecutively to the hospital for T1D and 1032 healthy subjects as controls were studied in Continental Italy and 284 subjects admitted consecutively to the hospital for T1D and 5460 healthy newborns were studied in Sardinia. PTPN22 genotype was determined by DNA analysis. Maternal age at conception and age at onset of disease were obtained from clinical records. χ² test of independence, student t test for differences between means and odds ratio analysis were carried out by SPSS programs. Three way contingency table analysis was carried out according to Sokal and Rohlf.

RESULTS: The pattern of association between PTPN22 and T1D is similar in Continental Italy and Sardinia: the proportion of *T allele carriers is 13.6% in T1D vs 6.7% in controls in Continental Italy while in Sardinia is 7.3% in T1D vs 4.4% in controls. The association between T1D and maternal age at conception is much stronger in Sardinia than in Italy: the proportion of newborn from mother aging more than 32 years is 89.3% in T1D vs 32.7% in consecutive newborn in Sardinia (P < 10^-6) while in Continental Italy is 32.2% in T1D vs 19.1% in consecutive newborns (P = 0.005). This points to an important role of ethnicity. A slight prevalence of T1D males on T1D females is observed both in Continental Italy and Sardinia. PTPN22 genotype does not exert significant effect on the age at onset neither in Continental Italy nor and Sardinia. Maternal age does not influence significantly age at onset in Italy (8.2 years in T1D infants from mothers aging 32 years or less vs 7.89 years in T1D infants from mothers aging more than 32 years: P = 0.824) while in Sardinia a border line effect is observed (5.75 years in T1D infants from mothers aging 32 years or less vs 7.54 years in T1D infants from mothers aging more than 32 years: P = 0.062). No effect of sex on age at onset is observed in Continental Italy while in Sardinia female show a lower age at onset of T1D as compared to males (8.07 years in males vs 6.3 years in females: P = 0.002).

CONCLUSION: The present data confirm the importance of ethnicity on susceptibility and on the age at onset of T1D.

Diagnostic accuracy of glycosylated hemoglobin in chinese patients with gestational diabetes mellitus: a meta-analysis based on 2,812 patients and 5,918 controls

BACKGROUND AND AIMS

The accuracy of glycosylated hemoglobin (HBA1c) detection for the diagnosis of gestational diabetes mellitus (GDM) has been extensively studied in the Chinese population, but the exact role of these detections remains controversial. The present meta-analysis was performed to establish the overall accuracy of HBA1c for the diagnosis of Chinese patients with GDM.

METHODS

After a systematic review of related studies, the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and other measures about the accuracy of HBA1c in the diagnosis of GDM were pooled using random-effects models. The summary receiver operating characteristic (SROC) curve analysis was used to summarize the overall test performance.

RESULTS

Forty-one studies included 2812 Chinese patients with GDM and 5918 controls were included in our meta-analysis. The summary estimates for HBA1c in the diagnosis of GDM in the studies included were as follows: sensitivity 0.762 (95% confidence interval [CI]: 0.746-0.777), specificity 0.917 (95% CI: 0.910-0.924), PLR 8.21 (95% CI: 3.77-17.89), NLR 0.20 (95% CI: 0.09-0.44), and DOR 41.40 (95% CI: 11.47-149.38). Our data showed that the SROC curve is positioned near the desirable upper left corner of the SROC curve, while the area under curve (AUC) was 0.93 with a Q* value of 0.865.

CONCLUSIONS

Measurement of HBA1c is likely to be a useful diagnostic tool for confirming GDM. The results of HBA1c should be interpreted in parallel with clinical findings and the results of conventional tests.

The role of PTPN22 C1858T gene polymorphism in diabetes mellitus type 1: first evaluation in Greek children and adolescents

Type 1 diabetes mellitus (T1DM) is an autoimmune multifactorial disease. Protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene encodes lymphoid-specific tyrosine phosphatase (Lyp), an inhibitor of T cell activation. PTPN22 C1858T polymorphism was associated with T1DM in populations of Caucasian origin. The aim of this study was the investigation for the first time of the association of PTPN22 C1858T polymorphism with T1DM in Greek population. We studied 130 children and adolescents with T1DM and 135 healthy individuals of Greek origin. The polymorphism was genotyped using polymerase chain reaction with restriction fragment length polymorphism. C1858T and T1858T genotypes as well as 1858T allele were found more frequently in patients (10.8% and 5.8%, resp.) than in healthy individuals (5.9% and 3.0%, resp.) but at non statistically significant level. There was no statistically significant association found with gender, age at diagnosis, severity of onset, history of Hashimoto thyroiditis or family history of T1DM. Increased frequency of 1858T allele in patients than in controls, implying a probable association, agrees with results of similar studies on other populations. The inability to find a statistically significant difference is probably due to the decreased frequency of minor allele in Greek population, indicating the need for a larger sample.

Association between the MDR1 gene variant C3435T and risk of leukaemia: a meta-analysis

Although a number of genetic studies have attempted to link the multidrug resistance (MDR1) C3435T polymorphism to risk of leukaemia, the results were often inconsistent. The present study aimed at investigating the pooled association using a meta-analysis on the published studies. 1933 cases and 2215 controls of 11 published studies in English before June 2012 were involved in the updated meta-analysis. Furthermore, subgroup analysis was performed in different ethnic and leukaemia subtype groups. This meta-analysis suggests that the MDR1 C3435T polymorphism associate with risk of leukaemia. The effect of the variant on the expression levels and the possible functional role of the variant in leukaemia should be addressed in further studies.